Why would you use some " wallet " ? You only want to store a private key!!!
For cold storage, you don't need a "wallet", you need paper or a usb key or something like that.
Perhaps the question should be what wallet do you use for importing a cold storage private key for signing transactions offline?
The whole point is, what if you could have a hot wallet that has the security of a cold storage single priv key?
Thats what trezor offers =)
Trezor allows you to have as many unknown wallets as passwords you can remember in your head. Better yet, a single mnemonic seed backs up all of those wallets. That seed would be the trezor's "cold storage" =) ... But unlike traditional cold storage, that single seed restores all of ur keys in all the wallets u created w/ trezor. Additionally, because trezor's seed is based on a BIP, its restorable via any wallet that correctly supports that BIP(in the case you dont have another trezor).
what if you can replicate this with another computer separated from your network, thus in a isolated enviroment but still connected to the internet, where you only do transaction of bitcoin and nothing else, so no browsing no DLing anything no clicking random link ecc...?
i firmly believe that with the right tools you can have an hot wallet that is secure like a cold walelt
Because I posted in this thread I had better state my opinion for the record, so it doesn't look bad later.
My opinion: allowing any third party other than that of the highest personal trust to handle your coin is a bad idea.
That includes: trezor, core, microsoft, armory, etc. etc. If you are talking cold storage, it shouldn't involve any of that crap. It's a freaking number man! Just keep it safe somewhere on your own. Is that so hard?
As to "hot" being " secure like cold" .. uh, no. Not that I don't recommend to hold funds in hot wallets, there is plenty of reason to do so, but do so knowing that there is an attack surface.
have you read what i've wrote after, how there can be an attack if you don't download anything and don't click anything on that machine? i'm not aware of any direct attack that work as a ddos or something that can steal your coins, without you allorw it...
also there is no way you can not allow a third party like you say to handle even for a small step your coins, because in the case of paper wallet you're doing so with the printer, which come probably from canon, epson or other known manufacturer
with usb is the same, they are made by someone else, unless you manage to make one your self, or do a whole pc yourself, i find this to be a stupid point, microsoft can't do anything on your windows machine, they can not control it, if that is your worry...